Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

Customer wants to tile the concrete floor throughout their entire basement. No problem, I said, but I'm wondering if I need a membrane such as ditra between the tile and the concrete, as the little voice in my head's telling me that slapping tile on thinset over concrete is unwise. What do you guys think?

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Re:
Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

Let me put it this way-- it never hurts to Ditra the floor. However, if that concrete's been there for years, and there's no real cracks in it, I'd go right on the concrete and not have a problem guaranteeing it. If there ARE any cracks, I'd check them to see if there are any with one side higher than the other. If that's the case, I wouldn't tile it at all, because NO membrane, not even the "legndary" Ditra, will protect the tile from vertical movement.

Ray-- I thought the same thing before I used it the first time. Schluter's rep had come to the local Dal warehouse and shown it to us, and my attitude was "Yeah, right. You got a bridge in your back pocket?" The first time I ever used it, it was due to a recommendation from Dave Taylor at tile-experts.com. There was someone who'd contacted him thru John Bridge's site from Rowley, Mass., who'd had a kitchen floor installed, and the guy came in and stapled 1/4" plywood over vinyl and luan. It took that floor 6 months to fail. So I went in tore out the old floor put down the Ditra and set glazed porcelain with unmodified thinset. There was so much I was doing on this job that went against everything I'd learned about tile to that point, that I had to get it in writing from Dave as well as the Northeast Schluter rep, Bryant Bouchard (the guy in the Kerdi video), that if this floor failed due to anything other than workmanship, they'd back me on it. That was almost 4 years ago, and that customer has already given me several other customers in her area, and I'm about to do a family room for another of her friends this april, so I know for sure that floor has held up fine. One other thing-- a week after that kitchen got tiled, a 450 pound Wolfe gas stove got wheeled across the floor.

The stove:

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Re:
Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

Quote:

Originally Posted by MattCoops

The reason why tile lasted so long in places like the ancient Egyptian pyramids is because they poured a layer of sand between the substrate and mortar bed. Much for the same reason as your thinking.

Good idea.

5,000 years of engineering theory can't be wrong, lol!

The job is for a close friend so we're not making a killing, but I'll definitely talk the guy into paying for a layer of ditra... I'd hate to see my work fall apart. Thanks everyone for the input and advice.

Re:
Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

You don't have to be. You've never heard of a sand cushioned floor? I've never done it with tile, but I've installed several sand cushioned terrazzo floors. The sand basically goes down just like drypack. The only difference is the cement is missing. It gets wet down just as much, packed, and screaded off the same way.

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Re:
Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

Ditra is fine, but why go through that hassle. ECB membrane for the floor is more than sufficient and installs in much much less time and hassle. Depending on the thickness, not only is it crack suppression membrane, but also can be water proof and sound proof. Great replacement for old cork installations in condo's that have cement floors.

I happen to disagree with bill vincent on the existing cracks or no existing cracks. Thermal expansion area's should be membraned or have expansion joints placed in the floor. Either premade metal with silicone or pure silicone expansion joints. If its a basement and they just don't care or do not have the extra money for membrane..then you can squeak by...but if its not a financial concern, membrane it. Worst case, if there are existing old cracks, then get some wicking paper or even small amount of membrane and cover those. Anything to prevent damage to the new installation for now and later.

Re:
Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

Ditra is ok . a few things i dont like about it
1 is the additional height added to floor
2 in wet areas where does the water go after gets through the grout and the thinset. answer is no where it sits in ditra channels and starts that horrible process we know as molding.
3 on large applications even an experienced installer can rarely smear thinset and then roll out ditra before overglazing. Not good for bond.

I do however always install a anti-fracture membrane over concrete in basements or smooth troweled concrete most thinsets even the best will shear from a smooth troweled or sealed concrete floor.

Have any of you used ardex yes ardex products for tile install or anti-fracture/waterproofing. there products are awesome maybe better than any i have used. for anti-fracture use ardex 8+9 is two part system you mix and roll or trowel on price is good also.

Re:
Installing Tile On A Concrete Floor In A Basement... Do I Need A Membrane?

Quote:

Originally Posted by stroventile

Ditra is fine, but why go through that hassle. ECB membrane for the floor is more than sufficient and installs in much much less time and hassle. Depending on the thickness, not only is it crack suppression membrane, but also can be water proof and sound proof. Great replacement for old cork installations in condo's that have cement floors.

About 10 years ago, I traveled around the country with a company out of Coral Springs, Fla. tiling malls for Simon DiBartello, and JC Pennys. Many of the malls we tiled got ECB throughout the mall. I spent many days going back to malls that were already completed with two or three man crews to replace tiles throughout the malls that had cracked as a result of the compression that the ECB allowed. After a a few malls giving us the exact same problems, they got away from using ECB.

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